Refrigerator



J. Ma KAYE 1,714,176

REFRIGERATOR Fil ed Nov. 12, 1926 4 Sheets-Sheet 1 May 21, 1929.

May 21, 1929. J, MacKAYE 1,714,176

REFRIGERATOR Filed Nov. 12, 1926 4 Sheets-Sheet 2.

May 21, 1929. I MacKAYE 1,714,176

REFRIGERATOR Filed Nov. 12, 1926 4 Sheets-Shee t 3 J. M KAYE REFRIGERATOR May 21, l929.-

Filed Nov. 12 1926 4 Sheets-Sheet 4 Patented May 21, 1929.

UNITED STATES 1,714,176 PATENT OFFICE.

JAMES MACKAYE, OF HANOVER, NEW HAMPSHIRE, ASSIGNOR T0 STONE A. WEBSTER, INC.,' 0]? BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

REFRIGERATOR.

Application filed November 12, 1926. Serial No. 147,919.

This invention relates to domestic refrigerators of the general type in which the cooling action is produced by the evaporation of water under a high vacuum.

The invention aims to improve refrigerators of this type with a view to avoiding the difficulties heretofore experienced due to m1- nute air leaks, to provide for the convenient manufacture, of small quantities of ice for table use or the like, and to devise a construction which will be more reliable, more completely automatic, and generally will satisfy the practical requirements for an ap aratus of this character more thoroughly t an prior constructions.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims. i

In the drawings,

Figure 1 is a view, partly in front elevation and partly in vertical cross-section, of a refrigerator constructed in accordance with this invention; 1

Fig. 2 is a cross-sectional view througha portion of the water tank and illustrates, in section, details of one of the float operated valves and the air bleed;

Fig. 3 is a plan view of the refrigerator shown'in Fig. 1 with the cover removed;

Fig. 4 is a vertical, cross-sectional view substantially on the line 44, Fig. 3; and

Figs. 5 and 6 are vertical, cross-sectional .Views through the upper part of the refrigerator on the lines 5-5 and 66, respectively, Fig. 3.

The refrigerator shown comprises a casing 2 having a. hinged top or cover 3 and doors 4 in the front thereof. This casing encloses a chamber orfcompartment to which access is afforded through the doors 4-4, this chamber usually beingequipped with suitable shelves (not shown) for the storage of food or other material to be kept cool. The walls, doors and cover of the casing may be'constructed in any suitable way to heat insulate the food chamber and the cooling apparatus mounted inside th'ecasing, but since the details of the heat insulating features form no part of the present invention they have not been illustrated;

' Inthis refri erator the food compartment cooled by a llquid jacket, preferably water,

the water in thejacket circulating around, and in contact with, a cooling unit which compr ses a container holding a body of water on whlch a relatively high vacuum is maintained. The evaporation so produced directly cools the water in the container and this, in turn, results in cooling indirectly the water in the jacket.

Referring to Figs. 1, 3 and 4 it will be seen that the water jacket nearly surrounds the food chamber and comprises a horizontal tank 6 at the upper end of said chamber, a shallow tank or chamber, and a series of fiat tubular sections or water columns 8 which are located on all four sides of the food chamber and connect the tank 6 with the header 7. It will be understood that the design and construction of the jacket may be varied according to the requirements of the particular refrigerator being built, much more heat absorbing surface being necessary or desirable in some cases than in others. The top of the tank 6 may be left open since it is protected by the heat insulating cover 3. A pipe 10, Fig. 6, conducts Water into the tank 6 and is equipped with a float valve 12 which automatically operates to maintain a substantially constant level of water in the jacket.

The unit which cools the jacket water is shown at 14 and it comprises a closed container holding a body of water and is located in the tank 6. Several vertical pipes 15 connect the top and bottom walls of the tank 14, while horizontal pipes 16 extend through it from one side thereof to the other. All of these pipes serve to stiffen the tank and strengthen it against collapse under the atmospheric pressure to which it is subjected, and, in addition, the horizontal pipes 16 provide for a circulation of the jacket water through the cooling unit. This container 14 is connected by a pipe line 17 of substantial cross-section, Figs. 1 and 3, to a vacuum pump 18 which is of a suitable type to maintain a relatively high vacuum in the container 14. Preferably a rotary pump is used. The pipe 17 should be large enough to operate without serious friction. The pump should be capable of maintaining an absolute vacuum of three millimeters or better of water in the container 14, and of handling a suitable volume of water vapor to produce the necessar refrigerating effect. The evaporation o the water in the container 14 will result in absorbing heat rapidly from the body of water therein, and'the cooling effect so produced will, in turn, cool the water in the jacket.

As the quantity of water in the container 14 becomes reduced by evaporation, it may conveniently be replenished from the jacket since water preferably is used as the circulating liquid. The admission of the water is controlled automatically by a needle valve 24, Fig. 2, operated by a float 25. Both the float and valve are mounted in a casing 26 which is connected to, but is located at one side of, the tank 14, as clearly shown in Figs. 2, 3 and 4. This fi'oat valve operates to maintain a substantially constant level of water in the container 14.

By mounting the cooling unit in a water jacket, as above described, and partly or wholly submerging the unit in the jacket water, much of the difficulty which has heretofore been experienced with minute air leaks into the vacuum tank is avoided. The container 14, in which the vacuum is maintained, can be made much smaller than otherwise would be required so that mechanical difficulties in making tight joints are reduced, a tank of sturdy construction can be manufactured economically, and the jacket water seals a substantial part of the container against minute leaks which otherwise would prove objectionable. Since the jacket is not subjected to heavy air pressure but is simply under a relatively low hydrostatic pressure, it need not be made of heavy and ex ensive construction.

11 order to provide for the convenient manufacture of small quantities of ice for table purposes, or making frozen desserts or the like, the refrigerator shown is equipped with a freezing unit in addition to the cooling unit above described. This freezing unit is shown at 28. It consists of a double walled container holding a body of water, the two walls being separated by air spaces 29 and 30, Fig. 5, which heat insulate the Water from the surrounding atmosphere in the refrigerator casing. The lower part of the container 28 is provided with a series of inclined holes or cavities 31. each adapted to receive a receptacle or holder containing the liquid or other material to be frozen or chilled. As shown, these receptacles or holders consist of tubes 32 removably fitting in the cavities 31 and each having a head or collar 33 to act as a stop for limiting their sliding movement into the inclined cavities. The front end of the freezing unit is located immediately inside one of the refrigerating doors 4. If desired a heat insulating door 34, Figs. 1 and 5, may be hinged to the freezing unit so that when closed it will furthe insulate this unit.

The freezing unit 28 sets into a Well or aperture 35, Fig. 3, formed through the tank 6, the unit having several supporting lugs 36 projecting therefrom and resting on the upper edge of the wall of the aperture or well 35. A small pipe or tube 37 connects the two containers 14 and 28 below their water lines so that the same water level is maintained automatically in both the freezing and cooling units, a vah'e 38 being included in this pipe connection so that one unit can be cut off from the other when desired. The freezing unit 28 also is connected to the pipe line 17 which runs to the vacuum pump 18 so that the bodies of water in the two units are subjected to the same degree of static vacuum. Two valves 39 and 40, respectively, are provided in the branch pipes which connect the main vacuum pipe line 17 to the two units, thus permitting the cutting off of either unit from the vacuum pump when desired for any reason.

It is preferable to add to the water in the cooling and freezing units some agent, such as glycerine, which will reduce the freezing point of the water. This is necessary in the case of the freezing unit because it is run at a temperature below the freezing point of water, and it is desirable from the standpoint of convenience to use the same liquid or solution in the cooling unit.

In order to increase the rate of evaporation of the water in the cooling and freezing units I' prefer to provide for the use of an air bleed or leak into said units in accordance with the disclosure made in the Mitchell Patent No. 1,549,918, granted August 18, 1925. If a sufficiently high vacuum is maintained the airbleed can be eliminated in the cooling unit.

Referring to Fig. 2 it will be seen that a valve casing 20 is secured tightly in the top of the container 14 of the cooling unit and is equipped with a needle valve 21 which cooperates with a seat therefor in the casing 20, the needle being so adjustable that only an exceedingly minute or restricted quantity of air will be allowed to pass through thevalve. The air so admitted is conducted by a pipe 22 down into the body of water in the container 14. The air which is allowed to leak into the water in this manner expands within the container 14 and is drawn out of this container substantially saturated with water vapor, thus increasing substantially the rate of evaporation of water and improving the efficiency of the apparatus very materially. Since. however, the air so admitted expands greatly within the container. it is important to regulate the air leak or bleed very accur: tely so that it will not lower the vacuum any substantial degree. For this purpose t is preferable to attach a conveniently observable manometer, or some equivalent measuring device. to the cooling unit 14 and to adjust the needle valve 21 so that air can be heard entering the valve while the degree of vacuum still ismaintained at a sufficiently high value, as for example, two or three millimeters of water. Or provision can be made for observing the passage of the air through the water. I prefer to use cotton or some other air filtering medium in the air valve casing to strain out dust particles and prevent them from lodging between the valve and its seat. As shown the valve is equipped with means to hold it in an adjusted position.

Essentially the same construction is used in the freezing unit 28. the air bleed valve bein; indicated at -12 in Figs. 3 and 5.

Vhen the apparatus is in operation it is necessary to run a lower temperature in the freezing unit than in the cooling unit, and this difference in temperature can be produced by adjusting the air valves 20 and 42 so that a greater air bleed or leak is permitted in the freezing unit than in the cooling unit. If a very efficient pump is used. and one capable of producing and maintaining a very high vacuum. and of moving a relatively large volume of attenuated water vapor. it may then be permissible to close the air valve 20 entirely so that no air bleed will be produced in the cooling unit. this unit being run under a static vacuum. A very small leak in the freezing unit then will so accelerate the rate of evaporation in this unit as to produce the desired difference in temperature in the two units. Or the air bleed in the cooling unit 14 may be made very small indeed, or microscopic. and that in the freezing unit 28 very slightly greater so that the desired temperatures will be maintained in the two units. The former method, however. is preferred. When the air valves 20 and 42 have once been adjusted to produce these results. no further adjustment of them is required, the temperatures being maintained automatically in the two units. If, however, the freezing unit is not to be used for a period of several months. as for example in the winter time. it may then be preferable to out off this unit altogether by closing the valves 39 and 40. In practice the vacuum pump is driven by an electric motor. and an automatic temperature controlling apparatus is used to govern the operation of the pump and motor, the pump being started into operation when the temperature in the food chamber rises above a predetermined point and being stopped again when the temperature has dropped below a predetermined value. Temperature controlling apparatus suitable for this purpose is widely used in connection with refrigerating machines.

The motor can be controlled either from the temperature of the water in the jacket or from the temperature in the food chamber as desired. In either event the fact that the food chamber is partly surrounded by a water jacket reduces the frequency ofthe starting and stopping operations, the j ackethaving a tendency to store up cold, to stabilize the temperature conditions in the refrigerator, and to reduce the effect of atmospheric temperature changes 011 the temperatures in the refrigerator. I

While the liquid used in the freezing and cooling units has been referred to as water, it will be evident from the foregoing description that this liquid preferably consists of water holding in solution a chemical, such as glyccrine, which has the effect of depressing the freezing point. Consequently, the word water as herein used is intended to include such solutions.

While I have herein shown and described the best embodiment of my invention that I have so far devised, it will be evident that the invention may be embodied in various other forms without departing from the spirit or scope thereof.

Having thus described my invention. what I desire to claim as new is:

1. A refrigerator of the domestic type comprising, in combination, a casing having a food chamber therein, a water jacket for cooling said chamber, a cooling unit in contact with the water in said jacket and around which said water circulates, said unit comprising a container for holding a body of water, means for automatically maintaining a substantially constant level of water in said jacket, a vacuum pump connected with said container and operative to maintain a relatively high vacuum therein, connections for admitting water from said jacket to said container, and a float operated valve controlling the flow of water through said connections in response to changes of water level in said container.

2. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit, each of said units comprising a closed container for holding a body of water, a vacuum pump connected Wit-h both of said containers and operable to maintain a relatively high vacuum in them, a refrigerator casing in which said units are mounted, said casing having a food chamber therein, a water jacket for cooling said food chamber, the water in said jacket being in contact with and circulating around said cooling unit, and a heat insulating jacket for said freezing unit, said freezing unit being arranged to receive a removable holder for material to be chilled.

3. A refrigerator of the domestic type comprising, in combination, a casing having a food chamber therein, means for cooling said chamber comprising a container adapted to hold a body of water, a vacuum pump connected with said container and operable to maintain a high vacuum therein, a heat insulating freezing unit in said casing adapted to receive a removable holder for material to he chilled, said freezing unit including a container for water, and pipe connections between said freezing unit and said pump whereby the pump is operative to maintain a high vacuum in said freezing unit.

4. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit, each of said units comprising a closed container for holding a body of water, a vacuum pump connected with both of said containers and ope able to maintain a relatively high vacuum in them, whereby said units are cooled by evaporation from the bodies of water which they contain, means for automatically maintaining a substantially constant level of water in one of said containers, and connections between said containers for maintaining the same water level in both containers.

5. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit, each of said units comprising a closed container for holding a body of water, a vacuum pump, pipe connections from said pump to both of said containers whereby said pump is operable to maintain a relatively high vacuum in them, and means for automatically maintaining a lower temperature in said freezing unit than in said cooling unit.

6. A refrigerator of the domestic type comprising, in combination, a cooling unit, a heat insulated freezingunit, each of said units comprising a closed container for holding a body of water, a vacuum pump, pipe connections from said pump to both of said containers whereby said pump is operable to maintain a relatively high vacuum in them, and means for accelerating the rate of evaporation of the water in the freezing unit.

7. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit, each of said units comprising a closed container for holding a body of water, a vacuum pump, pipe connections from said pump to both of said containers, whereby said pump is operable to maintain a relatively high vacuum in them, means for admitting air at a restricted rate into the water in said freezing unit, and means for automatically replenishing the supply of water in said freezing unit.

8. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit, each of said units comprising a closed container for holding a body of water, a vacuum pump, pipe connections from said pump to both of said containers, whereby said pump is operable to maintain a relatively high vacuum in them, and means for automatically replenishing the supply of water in said freezing and cooling units.

9. A refrigerator of the domestic type comprising, in combination, a cooling unit, a freezing unit adapted to receive a removable holder for material to be chilled, each of said units comprising a. closed container for holding a body of water, a vacuum pump connected with both of said containers and operable to maintain a relatively high Vacuum in them, whereby said units may be cooled by evaporation from the bodies of water which they contain, and means for automatically replenishing the supply of water in both of said units.

JAMES MACKAYE. 

